The field of the invention is knitting needles of the type used in knitting machines such as circular knitting machines. Such needles have a hook and hinged latch at one end. A shaft extends from the hook portion and a foot protrudes outwardly from the shaft. A plurality of such needles are used in a knitting machine and various needle holding and guide members are used to position and move the needles. The axial position of a needle is governed by the locating of the needle foot in a needle foot guide channel which may comprise a groove cut in the inner surface of a cylinder. As the cylinder rotates with respect to the needle holding member which holds the needles, a needle is caused to move axially in a predetermined manner by the camming action of the needle foot riding in the needle foot guide channel.
In an effort to improve the output of a knitting machine, higher operating speeds, resulting in an increase of the axial oscillation of the knitting needles has to be achieved. An increase in the axial oscillation velocity of the knitting needle and its associated increase in vibration stresses causes unacceptable breakage, especially in the hook portion of the needle.
Various methods have been utilized to help reduce needle breakage and, therefore, allow higher operating speed. One approach has been the addition of several bends in the needle shaft to cause a small amount of spring or give between the needle foot and the hook. Another approach comprises molding a plastic covering over the needle foot. Nylon 6, 6 has been used for this purpose and although this approach has permitted an increase in the axial velocity of the knitting needle, without the concomitant increase in destructive vibration, the life of such coverings is limited and thus the ability to increase the knitting speed has not been achieved.